1. Field of the Invention
The present invention relates to a printing apparatus (recording apparatus) that discharges ink from a print head (recording head) to a sheet to print an image, and to an ink supply method thereof. In particular, the present invention relates to a printing apparatus that prints an image on a sheet using an ink, a component of which easily precipitates, and to an ink supply method thereof.
2. Description of the Related Art
In U.S. Pat. No. 7,121,652, disposing a valve unit configured to open and close an ink supply path between an ink cartridge and a recording head to drive a suction pump with the valve unit opened is discussed. Further, opening the valve unit with a negative pressure accumulated in an internal space of a capping unit to generate quick flow of ink on an ink flow path from the ink cartridge to a nozzle opening of the recording head is discussed. Thus, enabling air bubbles remaining in the ink flow path in a state of being stuck to be released from the ink flow path is discussed. A method which reduces pressure on the recording head side from a valve on the ink supply path with the valve, provided on the way of the ink supply path, closed to open the valve with a negative pressure accumulated, thereby allowing ink to be supplied to the recording head is hereinafter referred to as “choke suction”. In U.S. Pat. No. 7,121,652, as ink, black, cyan, magenta, and yellow inks are discussed. However, any component of ink is not discussed therein.
In a printer which uses ink a component of which easily precipitates, it is required to stir the ink to make the density of ink uniform. As a configuration to stir ink, there is a configuration in which a user operates an operation knob to stir ink in an ink pack and then attaches the ink pack to the printer. When the above-described choke suction is intended to be performed on the printer using ink a component of which easily precipitates, the user needs to operate the operation knob to stir ink and then perform the choke suction to supply ink to the recording head. Accordingly, the choke suction is performed after ink is stirred. Thus, there is an issue to require a long period of time until the printer is brought into a usable state.